This invention relates generally to a folding knife having a spring-assisted blade opening mechanism.
The present invention includes a folding knife comprising a handle; a blade pivotally connected to the handle for movement between an extended position extending outwardly from the handle and a retracted position adjacent the handle; a spool connected to the blade for movement with the blade, the spool defining a plurality of attachment openings; and a spring connected to at least one of the attachment openings of the spool and to the handle, the spring urging the blade towards the extended position.
Folding knives are popular due to their compact size and portability. However, a potential drawback of certain folding knives is that they require two hands for use. One hand is required for holding the handle portion of the blade, while the other hand is necessary to withdraw the blade from its retracted position within the handle and move the blade to the extended, operable position.
Accordingly, it is desirable to have a folding knife wherein the blade can be opened using one hand. One such folding knife design is disclosed in Applicant""s U.S. Pat. No. 5,815,927, issued Oct. 6, 1998, and entitled xe2x80x9cFolding Knife With Actuatable Safety Locking Mechanism.xe2x80x9d That design allows the user to extract blade from its retracted position within the handle by the user""s engaging and pulling on ridges defined in a rear portion of the blade. A plunger mechanism having a coil spring facilitates opening of the blade, but the user is still required to pull on the ridges in order to move the blade through a selected range of motion and for the spring to assist the blade to move it to the extended position.
Providing a folding knife design wherein the blade may be opened using only one hand produces obvious advantages. The user is allowed to use one hand for holding, pulling, or pushing on the object to be cut while at the same time being able to withdraw the folding knife from his or her pocket, toolbox, or some other compartment and moving the blade to an extended, usable position. Another advantage is for disabled persons who may have only one arm or one functioning hand. Further, law enforcement and military personnel may find a folding knife which may be operated with one hand useful in performing their duties.
Numerous folding knife designs have been patented. For example, U.S. Pat. No. 273,858, issued to Korn, discloses a folding knife having a leaf-type spring for moving a blade to an extended position. U.S. Pat. No. 1,603,914, issued to Hermann, discloses a folding knife having a coil spring connected to a metal tape, which pulls the blade to a retracted position. U.S. Pat. No. 2,601,999, issued to Sly, discloses a foldable gaff hook having a similar opening mechanism. U.S. Pat. No. 2,407,897, issued to Newman also discloses a spring for pivoting blade open upon actuation of a locking lever. U.S. Pat. No. 698,080, issued to Treas, also discloses use of an actuating spring for pivoting a blade to an open position.
U.S. Pat. No. 4,535,539, issued to Friedman, et al, and U.S. Pat. No. 5,093,995, issued to Jan, disclose button release mechanisms for folding knives.
U.S. Pat. Nos. 4,893,409 and 5,964,035, issued Poehlmann, disclose folding knives having adjustment screws for adjusting the fit of the blade in the extended position. U.S. Pat. No. 1,065,863, issued to Carter, also discloses use of set, or an adjustment, screw.
It is, therefore, the principal object of this invention to provide a folding knife which can be opened by the user using only one hand.
Another object of the present invention is to provide a folding knife which opens automatically upon actuation of a release mechanism.
Still another object of the present invention is to provide a folding knife whereupon movement of the blade to the extended position causes the blade to be automatically locked in the extended position.
A still further object of the present invention is to provide a folding knife having a release member located on the back of the handle, such that depression thereof causes the blade to automatically move to the extended position.
A further object of the present invention is to provide a method of assembling a folding knife.
Another object of the present invention is to provide a method of extending a blade of a folding knife.